1. Field of the Invention
The present invention relates to a liquid fuel tank and, more particularly, to a double-shell tank having fuel absorbent material disposed between an inner shell and an outer shell, and to such a tank made of molded plastic material.
2. Description of the Related Art
In the design and construction of fuel tanks, the avoidance and prevention of leakage is a matter of utmost concern. When a tank is used in a motor vehicle to store fuel, such as gasoline, it is particularly important that the tank should be able to sustain an impact without releasing its contents.
Improved plastics molding techniques have made it possible to manufacture fuel tanks made of plastic material. As with older metal tanks, such plastic tanks must also be made to prevent the escape of the fuel contained within.
In the past, tanks have been constructed with an outer envelope and sealing compound beneath the outer envelope. If the tank is penetrated, the sealing compound flows together to close the hole. If, however, the inner tank leaks, the escaping fuel is not absorbed by the sealing compound. Also in the past, tanks have been constructed with an outer envelope and layers of sponge rubber beneath the outer envelope as a shock absorbing material. The sponge rubber is not effective in taking up any fuel leaking from the inner tank.